Magento2 How to resize product images by product id without using resize command

Question

Does any one know how we can resize product image by product id ? i do not want to use resize command,becuase it takes much time

Answer 1

protected $_productRepository;
protected $_productImageHelper;

public function __construct(
    \Magento\Backend\Block\Template\Context $context,        
    \Magento\Catalog\Model\ProductRepository $productRepository,
    \Magento\Catalog\Helper\Image $productImageHelper,
    array $data = []
)
{
    $this->_productRepository = $productRepository;
    $this->_productImageHelper = $productImageHelper;
    parent::__construct($context, $data);
}

public function getProductById($id)
{
    return $this->_productRepository->getById($id);
}

public function getProductBySku($sku)
{
    return $this->_productRepository->get($sku);
}

/**
 * Schedule resize of the image.
 * @see \Magento\Catalog\Model\Product\Image
 * @param int $width
 * @param int $height
 * @return $this
 */
public function resizeImage($product, $imageId, $width, $height = null)
{
    $resizedImage = $this->_productImageHelper->init($product, $imageId)
                    ->constrainOnly(TRUE)
                    ->keepAspectRatio(TRUE)
                    ->keepTransparency(TRUE)
                    ->keepFrame(FALSE)
                    ->resize($width, $height);
    return $resizedImage;
}